Method for forming molded objects



A. E. GIBSON METHOD FOR FORMING MOLDED OBJECTS Sept. 7 1926.

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. My invention has for its ob'ect the molding of artificial teeth and oter objects in such a manner as to form them of two or more rades ofmaterial (such as of di'erent co ors) and which, when baked o r vitri-Alied, will provide a unitary object with differentcolors or shadesblended toa greater or less degree.

My object is further "to provide a suitable machine or apparatus toinsure theproperassemblage or mixing of the materials from which theteeth or other objects are to be molded and for putting the same undercompression in molded form preliminary t o s ubsequent treatment such asbakin .or vitrifyv in according to the use of the o ject. I

onsidering the subject of this invention more particularly in respect tothe making of artificial teeth, it is necessary torovide a porcelain`darker material than the front and incisor portion which are composedof lighterhand more transparent porcelain.

Heretofore, the material composing fthe light and dark portions of theteeth is fi.rst prepared in a more or less pasty condition and thenintroduced successively by hand in the mold and subsequently pressedandbaked preliminary to the final and vitrifying operation. The process, asheretofore carried on, is relatively slow and moreover is liable toprovide more or less irregularity and dissimilarity in the shading ofthe teeth when they should be duplicates of each other.

By my improved process and means, l am enabled to mold such teeth in arapid manner from a powdered or granular material` and at the same timeinsure absolute uniformity in the 4deposition of the materials in i0 themold for insuring the different coloring or shading of the article. vFurthermore, by my improved process and means for carrying the sameintoeffect, am enabled to subject the material to great l5, pressure so thatthe said material in granular form is so compacted that it is brought toa strong molded shape which may be readilyhandled without the necessityof a preliminary baking operation, as has heretofore i0 been necessarywith hand molded teeth.

With the above and other objects in view, the nature of Vwhich will bemore fully understood from the description hereinafter, the inventionconsists in the novel method vbody portion of a re ativelyv andconstruction of means for molding objects, as hereinafter more fullydescribed and defined in the claims.

Referring to the drawings: Fig. 1 is a sectional view of the coo rativeportions of a machine adapted for t e practice of my improved processand embodying the structural characteristics of the preferred form ofapparatus embed ing my'invention; Fig. 2 is. a plan view o the same withthe upper d1es removed; Figs. 3, 4, 5, 6, 7 and 8 are vertical sectionalviews of the main dies andV the materials operated upon for illustratingthe severa-1 steps in the process; Fig. 9 is a sectional view of amodification; Fig. 10 is a sectional view of a completely molded toothform with anchory imbedded and ready for receiving the anchor pin; andFig. 11 is a perspective view of the die structures employed in Figs. 3to 8, inclusive.

. 2 is the main frame and is provided with a vertical aperture 3 inwhich a vertically reciprocable annular die body 4 is adapted to bevertically adjustable under the operation of an oscillating levermechanism 5 intended toraise the body 4 to at least the positionindicated in Fig. 1 or to lower the same to expose the upper part of thedie 6, as may be required. The lower die member 6 is guided within thebody4 and is adjustable vertically by means of a pivoted lever structure9. The lower portion of this die member 6 is fitted within a spool 7having an adjustable nut 7 at the top and a flanged lower porl Ation,and between which flange and nut there is a loose sleeve 8 to whichthe'lever structure 9 is hinged and by which motion is imparted to the diemember 6. The lower i part of the spool is provided with an adjustableabutment screw 6 by which the die member 6 may be adjusted verticallywith respect to the spool. When the spool 7 is 1 fully down, it restsupon the part 2m ofthe main frame 2, said part 2 constituting anabutment for sustaining the die member 6 during the vdownward thrust ofthe male die member 19, to be later described. By providing theadjustable abutment screw 6'L and the adjustable nut 7 capacity foradjusting the position and movement of the -die member 6 vertically ishad to control the thickness of the article being molded, as more fullydescribed hereinafter.

The main frame 2 is provided with a table 24 having a levelcorresponding to the upper surface of the body member 4 of the diestructure when fully raised for' die action, as indicated in Fig. 1.Rotate-bly supported upon this table is a mechanism 25 for feeding thematerials to be molded from hoppers 40 and 4l into the space of the diemember 4, as will be understood from the drawings. This mechanism 25 issecured to a vertical shaft 32 journaled in the main. frame and providedat its lower end with a coil spring 33 which pulls the mechanism 25 intoa snug fitting with the top of the table 24 and upper surface of thebody member 4 of the die structure when raised. More specifically, thisfeeding mechanism 25 comprises two oppositely directed curved feedingpassages 26 and 28 respectively provided at their lower ends withdischarge openings and 31 which are closed or sealed by the surface ofthe table 24 and upper surface of the body member 4, except when broughtdirectly over the aperture in the body member 4 of the die structure, asindicated in Fig. 1. As shown, the curved passage 26 may terminate atits upper end in a hopper 27, whereas the curved passage 28 terminatesin a larger annular hopper 29 surrounding the hopper j 27. These hoppers27 and 29 are respecinto th the two materials into the unitary aio'fitted with a shaping die 17 tively supplied with molding materials Aand B from the containers 40 and 41 which discharge into the hoppers.mechanism 25 may be rotated by a bevel gear 35 on a driving shaft 36meshing ywith a bevel gear 34 on the feeding mechanism itself.

During the operation of the machine, this feeding mechanism may berotated continuously or intermittently, as preferred, so that itdeposits within the die structure a measured amount of the material Aand `after the same has been adjusted b part compression, it deliversthe other material B e space thus provided within the die structurebefore the final compression of body, all of which will be fullyunderstood fromva later description of the operation.

At a point above. the body member 4 of the die structure lis arrangedany suitable form of mechanism for vertically reciproeating a pair ofmale die members 17 and 19, alternately.A In the particular mechanismillustrated, 14 is a vertical reciprocating head which may be guided inan extension of the main frame and put into action by any of the usualmechanisms employed in stamping 0r die process. Pivoted to the bottom ofthe head 14 on a. vertical stud 16 is an adjustable die carrying frame15 having two sockets respectively upon opposite sides of the stud 16and one of which is having a lower other provided its end surfaceinclined surface 18, and the with a plunger die 19 having The feedingshaped to conform to the upper part of the finished molded object. Thedie carrying frame or turret 15 may be rotated about the Stud 16 by agear 22 meshing with gear teeth 21 about said frame, the latter teethbeing of relatively great vertical height so as to permit verticalreciprocation relatively to the operating gear 22. spring actuatedplunger 23 in the head 14 may be employed to coact with holes in theupper part of the turret frame 15 to centralize the dies 17 and 19 overthe aperture in the die ,body 4 and over bottom die member 6, as will beunderstood by reference to Fig. 1.

When this invention is employed to mold artificial teeth, it is usuallynecessary to embed within the bisk body a platinum pin or anchor andprovide a hole leading thereto from the back of the tooth and to providethese results, l employ the following devices: Extending upwardlythrough the lower die member 6 is a stationary rod 10, the lower endthereof being adjustably attached to the main frame 2 at 11 and at theupper end there is a slightly tapered post portion 12 which projectsabove the upper surface of said die member 6 and adapted to support theanchor 13, of whatever form the anchor is to be placed on the post, thebody member 4 is moved downward upon the lower die member 6 so as toexpose said post 12 to permit the application of the anchor byl hand orautomatically as maybe desired, 1 in no way confining myself in thisrespect. When the bisk tooth has been molded (as described hereinafter)the die member 6 is raised, therebylifting the tooth and its anchor fromthe' stationary post. The adjustment of the 1t may be. When rod 10vertically is to not only insure theproper projection of the post 12within the mold space, but where the lower die membei' 6 is adjusted asto its vertical movement to insure a greater or less quantity of thematerials A and B being received in the body member 4 to provide aresulting bisk tooth of greater or less thickness, as required, this rod10 must be correspondingly adjusted to maintain the proper predetermineddepth of embedment of the anchor. The adjustment of the die member 6 issecured bythe abutment screw 6 and the nut, either or both, as desired.

The general operation of the process and.

molded by the cooperation of the members 4,

.6, 17 and 19, upon materials A and B supplied by the feeding mechanism25j, and moreover, further provided, if desired, with the anchor 13 inplace and an aperture 13 leading thereto (as indicated in Fig. 10) thefollowing procedure is had. The feeding mechanism 25. supplies the Amaterial through the conduit 26 and a rture 30 into the space within themold bo y 4 and above the bottom die member 6'; as indicated in Fig. 1..It will be understood, however, that the configuration of the top ofthe bottom die member' and the bottom 20 of the male die member 19 areshaped to correspond to the back and front surfaces lof the toothformation to be produced, and further that the anchor 13 had been placedupon the end of the post 12 of the stationary rod 10, so that lthe saidanchor will be molded within the tooth body. Vhen the space within thedie body 4 has been filled, the feeding mechanism 25 is rotated toexpose the upper surface of the body 4. Thereupon, the packing orshaping die 17 descends and entering the body member 4, causes thematerial A therein to be .crowded laterally and somewhat packed downupon the lower die member 6, as will be understood by reference to Fig.5. This provides a space above the material A and within the body member4 into which material B may be supplied when the shaping or forming die17 has been raised, and the feeding mechanism 25 given a semirevolutionto bring the orifice 31 over the upper opening into the body member 4,as will be understood by reference to Fi 6.

During the operation of vfee ing the B material into the die member 4,the turret frame 15 may be rotated so as to bring the male die 19 intoposition immediately'above the lower die member 6 and the aperture ofthebody member 4; and as soon as the feeding mechanism 25 has beenturned to expose the material contained within the body member 4, thehead 14 is depressed with the result that the male die 19 is drivendownwardly upon the combined material A and B and compresses it into thecondition illustratedin Fig. .5, and as more fully shown in Fig. 10,wherein the A material is compressed to the toothform A and the Bmaterialcompressed to vthe form B. The portion A constitutes the bodymaterial of the tooth and is more or less colored to -imitate theshading of natural teeth, Vwhereas the portion B constitutes the frontor enamel portion of the tooth covering the body part at the middleportion and extending. beyond it at the lncisor end. Similarl-y, thedarker .or body portion A of the material extends beyond the enamelportion B and at the upper or root end ofthe tooth. The materialscomposingthe parts A" and desired shade.

B may be of the same general composition,

for example, feldspar, kaolin and silex, eX-

cept for the coloring metallic oxides employed in the two parts for`imparting the When the compression of the materialv between the diemelnbers 6, 19, is being completed Fig. 7). the spool 7' which sustainsthe ower die member 6 rests directly upon the abutment 2'* of the mainframe to provide a firm foundation. When the compression has beencompleted, the male die member 19 is raised clear of the body member 4and thereupon the .lever mechanism 9 is operated to lift the lower diemember 6 to bring the molded tooth tothe level of the table 24 and topof the body member 4, as indicated in Fig. 8. When this is done, a blastof air from' the nozzle 39 will remove.the molded tooth from the d1es byblowing it therefrom and into a suitable receptacle. During'the raisingof the member-6, the molded tooth form with its contained anchor 13 israised from the stud 12 of the pin 10, so that when the tooth form isfully raised, it will contain the anchor and be provided with the hole13 leading thereto, as shown in Fig. 8. I

It will be observed from reference to Figs'. 3 and 4 that when thematerials A and B are introduced within the body member 4, the materialA will extend practically for the full area of the lower die 6. It willalso be observed l'rom Figs. 7 and 8, that when the die 19 compressesthe material, there will be a tendency for the Bnlaterial at the lowerpart to crowd the A materialto the right and for the A material-at theupper portion to crowd the B material to the left, with the result thatwhen the complete compression ot the dies takes place, the A material inthe part A will extend to the right ot the B material in the part B',and similarly, the B material in the part B will extend to the leftbeyond the A material in theJpart A', as is clearly indicated in Fig.10. The result of this is that the incisor portion of the tooth haspractically little coloringmatter associated with it, whereas the rootor gum end'of the tooth has a pronounced coloring which not only showsdirectly but also through the finer porcelain facing material B. Whenthe bisk tooth thus formedis vitritied, the coloring matter blends intothe porcelain facing portion B, and thereby makes the shading orcoloring gradual with `the deepest shade at the root or gum end and thelighter shade toward the incisor end.

vIt will be understood that when the A material is in the body moldandthe die 17 descends to slightly compress the said material into thecondition indica-ted in Fig. 5,

there will be some tendency to crowd a portion of the 'material upwardlyand laterally `upon the upper surface of the body mold part 4, becauseof theinclined nature of the surface 18 of the die 17. If this occurs,the

forward edge 37 of the feeding mechanism 25 will sweep said extrudedmaterial over the table and discharge it at 38, as will be more fullyunderstood by reference to Fig. 2.

It is tojbe understood that, while this iu- 'vention is especiallyadapted for the mold- 130 ing of artiicialteeth in a rapid manner, it isnot restricted to that use, as the dies may be made of anyshape desiredfor articles of various forms and which r uire porcelain or similarmaterials ofl di erent shades. For example, the two characters ofmaterial A and B may be employed in connection with die work. whichwould correspond to what are known as cameos wherein the relief portionwould be of the li hter material B and the body or backing of t e darkermaterial A. This reference to other possible uses of the invention willindicate the capacity for various purposes for which the invention maybe employed. This invention, in a generic sense, is intended to coverthe process and means for molding a plurality of materials in a more orless powdered form into such relation that the may 'impart differentcoloring effects to t e unitary articles as molded, whether the shidarticle is subsequently vitrified or not. The invention also extends toand includes the articles produced, that is to say, in a generic sense,a molded article formed of compacted powdered materials, whereb said twocharacters of materials mechanically unite and overlap, so as to providethe dual colors desired, whether the same is made in the form of anartificial tooth or otherwise, and also including the structure whetherit is vitrified or merely hardened under compression or in any othermanner.

lVhile the general character of porcelain composition is well lmown andit will be understood that any of such compositions may be employed incarrying out my improved process, I will, however, state that for thepowdered or granular material constituting the A and B materials of theprevious description, the A material may be composed of a mixture offeldspar with kaolin and silex and to which is added a suiiicientquantity of metallic oxides to provide the requisite coloring orshading, the same constituting the dark material A of the object to beproduced. On the other hand, the B material which constitutes the lightmaterial B of the object may be of identically the same composition,except so far as the coloring oxides are concerned, which may be omittedif desired. Aside from the mixtures of these earthy or mineral matters,the' powders should be mixed with small quantities IofV a suitablebinder, such as is provided by a solution of um arabic, sugar water,rosin, wax, dextrin or other equivalent vegetable matter or any mixturesof them desired, so that when the materials A and B are compressed inthe dies, they will maintain their shape with suieient rigidity to'beeasily handled, and, furthermore, the A and B material will adhere toeach other. Before these mixtures are employed in theV dies, they arepreferably .rubbed through a fine sieve so as to be relatively finelydivided and of small granular form, permitting easy and satisfactory usein a machine of the character described. It will also be understood thatwhile in the making of artificial teeth the B material will requirelittle or no coloring oxides, nevertheless, in the making of cameos orother ornamental objects suitable coloring matters may be employed withboth the light and dark materials in the finished object, and I,therefore, do not limit myself in respect to such a-dmixture.

As it is quite important that the incisor end of the tooth shall havedifferent coloring matter than the body part, I may, as an additionalimprovement in my invention, provide means for introducing into the moldbody at the incisor end of the mold, a small quantity of the B materialbefore the A material is introduced. This preliminary introduction of Bmaterial at B2, Figs. 1 and 3, to constitute the B3 part in the tooth(Fig. l0), may be accomplished in the following manner. The die bodymember 4 is provided with a vertical passage 4a opening at the uppersurface of the said body member and at the bottom opening sidewise at 4bthrough the side wall to the interior of the mold space adjacent to theincisor end thereof. When the feeding mechanism 25 rotates to feed the Bmaterial into the interior of the mold space within the body member 4,it also feeds some of the same material into the passage 4*l because theorifice 31 is suliciently wide to permit this action.

The feeding orifice 30 for the A material is not wide enbugh to openinto the passage 4a and consequently the A` material never enters thesaid passage. IVhile the B material is delivered both into the moldspace of body member 4 and into the passage 45 at the same time, thatwhich enters the passage 4a is not delivered into the mold space untilthe next molding operation.

Assuming a tooth has just been molded and ejected and the mold members 4and 6 are again'in position shown in Fig. 1. As the feeding mechanism isthen clear of -the body member A, the latter is slightly raised by thelever mechanism 5 to bring the lateral port 4b up just enough'todischarge some of the B material in the passage 4 into the mold spaceimmediately above the 4face of the lower die member 6 and at the lateralend thereof corresponding to the incisor end of the tooth said depositedmaterial being indicated at B2, Figs. l and 8. The body member 4 is thenlowered to position shown in Figs. l and 4. The feeding mechanism 25 isthen moved to discharge the A material into the remainingxspace in thebody member as shown. Then the descent of the male shaping die member 17not only crowds the A material to the right but shapes the B material atB2 also, as shown in Fig. 5. Thereafter the further quantity-of the BllO material. is introduced as in Fig. 5. Thereafter the die 19 isbrought into action and Completes the compression and the i'iualprocedure is the saine as before described. B material ot the B and llparts ot the tooth is in ell'ect one body when the full compression hastal-:en place, but l have indicated its location by reference letters inFig. S for better understanding.

It will also Abe understood that while soldered pin teeth require theanchor 13 to be made a part of the tooth and to which the pin-issubsequently soldered, the teeth produced by my improved method andmeans may have pins directly molded iii the teeth and anchors omitted.To secure this result theupper end ot' the bottom die member 6 isprovided with a shallow hole 13, Fig. 9, into which the pinA is placedwith the head thereof extending upwardly. The molding operationotherwise is the saine as efore and when the tooth is removed from thedies, the pin is withdrawn with the tooth.

While I refer that thc material introlduced into t e dies at B2 shall beof the same Vthe natural teeth.

'It is pointed out that while the rod 10 provides the post upon whichthe anchor 13 is supported within the mold space during the vmoldingoperation, and that the said post also acts as a core for molding a holein the back of the tooth or other object, it will be understood that theanchor 13 may be omitted and the end of the rod V10`utilized in merelymolding a hole in the tooth or obf ject from the back, such as is commonin diathoric teeth.

Considering the broaderscope of the invention, it will be understoodthat I am not coniined to the particular method of intro- A ducing thematerials A and B into the mold space, as said materials A and B (and ifdesired B2) may be introduced into the mold space, `as in Fig. 6, in anymanner desired and without use of the forming die 17, relysiderablylighter in color than the A material.

No claim is made in this application'to the apparatus herein describedfor the The quirements of the invention and on account o t economy ispreferred in commercial practice, but I. do not restrict or confinemyself to the minor or secondary details either as to the method ofprocedure or the means employed in putting it into effect, as variationstherein may be resorted to as matters for the skilled artisan andwithout a de# parture from the spirit of the invention.

Having now described my invention,what I claim as new and desire tosecure by Letters Patent is: l

1. The method of molding objects from a plurality. of materials insubdivided condition having different colors or shades for producingblended color or shade effects along the length of the finished obiect,consisting in successively feeding into a laterallyconining mold spacethe plurality of materials of different color or shade in a granularcondition and so disposing them one upon the other as to be superposedat the middle and overlapping at the opposite ends so that the endportions of the finished article are tapering and each composed of adiii'erent one of the materials only, and subjecting said materialswhile maintained in overlapping condition at opposite ends tocompression between oppositely approaching die walls to compact them.into a unitary mass while temporarily confined within'the mold space.

2. 'I he method according to claim 1, wherein the molded object therebyproduced is subsequently vitriiied and blended by being subjected to ahigh temperature capable of fusing the two materials into a blendedstructure.-

3. The method of molding objects from a plurality of bodies of materialsof the same general composition but of different shade or color,consisting in first introducing the material in granular condition anddesired shade or color into the mold space of a suitable mold and upon acompressing die surface, then shifting the said material lat-erally sothat the greater portion of it will be positioned at one side of themold space and partly compressing said material, then introducinganother portion of the material in granular condition and of lightershadi-v or color into the mold space and upon the compressed iirstmentioned darker material whereby it is so disposed that the greaterportion of its -mass will be positioned at the opposite side of the moldspace, and there- 4. The method according to claim 3,

wherein further the molded objectis removed from the mold and lirstsubjected to a baking action to dryit out, and finally to a highertemperature to vitrify the object.

5. The metho'd according to claim 3, wherein the material firstintroduced 'into the mold space and compressed is compacted about ananchor and a p ost supporting it` and thereafter whennthe completedobject is molded withdrawing the object and the anchor from the moldspace dies and post leaving a hole leading'to the anchor, andsubsequently vitrifying theobject.

6. The method of molding an object from two materials having differentshade characteristics which consists in introducing 1nto the mold Vspacea metallic anchor and supporting it upon a post, closing the mold spaceat a short distance below the anchor, introducing into the mold space amaterial in granular form which completely covers and embeds the anchortherein, partially compressing theV said materialY upon and about theanchor and post, thereafter introducing' a second body of material alsoin granular form of a lighter shade or color than the material in whichthe anchor is embedded, subjecting the materials toY compression betweendies while confined within the mold, and removing the molded object Y.

from the dies and post whereby it contains the anchor embedded wholly inone of the materials and having an opening from the anchor leading tothe outer surface of the objectand through the material in which theanchor is embedded, and finally vitrifying the molded object into a hardunitary structure.

7. The method of molding objects from a plurality of materials insubdivided condition having different colors or shades for producingblended color or shade effectsv along the length of the finished object,consisting in successively feeding into a laterally confining mold spacethe plurality of materials 'of dlferent color or shade and so disposingthem one upon the other as to be superposed at the middle andoverlapping at the ends so that the end portions are tapering and eachcomposed of one of the materials onl and subjecting said materials tocompression between oppositely approaching walls to compact them into aunitary mass while temporarily confined within the mold space, andwherein as a preliminary operation a small quantity of material fromwhich the object is to be formed is introduced at one end of the moldspace before the successive plurality of different materials aresuperposed. y

8. The method of molding objects from a plurality of bodies of materialsof thesame general composition but of different shade or color,consisting in first introducing the material of darker shade or colorinto a suitable mold andupon a compresslng dle surface, then shiftingthe said material laterally so that the greaterY portion of it will bepositioned at one side of the Y mold space and partly compressing saidmaterial, then introducing the material of lighter shade or color intothe mold and uponthe compressed first mentioned darker material wherebyit is so disposed that the greater portion of its mass will bepositloned at the opposite side ofthe mold space, and thereafter whilewithin the mold space slmultaneously compressing both materials whollybetween compression dies having oppoised irregular die surfaces andmovable within the mold space and so that a unitary object independentof the shape of the mold space is produced, and further characterized byintroducing into the mold space at one end thereof a small quantity ofthe material to enter into the article, said introduction made prior tothe introduction of the materials into the mold space.

9. The method of molding an object from a plurality of materials in moreor less granular form consisting in supplying thematerials Yto the moldsuccessively and in different quantities, the materials first and lastintroduced being of one character as to quality and the materialsintroduced intermediate of said first and last introductions of materialhaving another quality and subjecting the two materials of differentqualities first introduced into the mold to a shaping and moderatecompression, and thereafter upon the introduction of the final materialsubjecting all of the materials to a heavy pressure to bring them intothe proper shape for the finished article.

1Q. The method according to claim 9, further characterized byrestricting the material first introduced into the mold to a relativelysmallY proportion of the whole material employed and locating it closeto one end of the mold space, whereby in the completed object iswithdrawn, the anchoring means is removed with the molded object as aunit therewith.

12. The herein described method of orming an artificial tooth havingdifferent shades of material along its face blended into each other andthe respective shades extended beyond the blended portions to form endportions Vof different shades, the same consisting in successivelyfeeding into a confining mold space two'bodies of Inaterial of differentshades one of said bodies of material being largely' massed toward oneend of the mold space and the other ot' said bodies of material beinglargely massed at the opposite end of the mold space, and simultaneouslycompressing the two bodies of material in their overlapping positionsbetween two die portions relativel movable in opposite directions withint e mold space and compressing the said materials of different shade uon each other, and in which a portion o each of the materials ofdifferent shade respectively extends beyond or overlaps the materials ofdifferent shade which are blended whereby the incisal end and cervicalend of the molded tooth structure yare respectively formed of materialsALBERT E. GIBSON.

